letter_list='ABCDEFGHIJKLMNOPQRSTUVWXYZ'
def Get_KeyList(key):
    key_list=[]
    for char in key:
        key_list.append(ord(char.upper())-65)
    return key_list
print(Get_KeyList("ABCDEFGHIJKLMNOPQRSTUVWXYZ"))
def Encrypt(plaintext,key_list):
    ciphertext=""
    i=0
    for ch in plaintext:
        if ch.isalpha():
            if ch.isupper():
                ciphertext+=letter_list[(ord(ch)-65+key_list[i]) % 26]
                i+=1
            else:
                ciphertext+=letter_list[(ord(ch)-97+key_list[i]) % 26].lower()
                i+=1
        else:
            ciphertext+=ch
    return ciphertext

print(Encrypt("hello,world",[7,3,8,2,8,3,6,3,6,8]))
